Raman spectroscopy of newberyite, hannayite and struvite

Abstract

The phosphate minerals hannayite, newberyite and struvite have been studied by Raman spectroscopy using a thermal stage. Hannayite and newberyite are characterised by an intense band at around 980 cm -1 assigned to the ν 1 symmetric stretching vibration of the HPO 4 units. In contrast the symmetric stretching mode is observed at 942 cm -1 for struvite. The Raman spectra are characterised by multiple ν 3 antisymmetric stretching bands and ν 2 and ν 4 bending modes indicating strong distortion of the HPO 4 and PO 4 units. Hannayite and newberyite are defined by bands at 3382 and 3350 cm -1 attributed to HOPO 3 vibrations and hannayite and struvite by bands at 2990, 2973 and 2874 assigned to NH 4 + bands. Raman spectroscopy has proven most useful for the analysis of these 'cave' minerals where complex paragenetic relationships exist between the minerals.

Influence of tempereature on Struvite precipitation by CO2‐deagassing method

“…The identification of struvite precipitated as a single phase was confirmed by infrared analysis (figure not shown). The experimental data are in full agreement with the recent publications [16][17][18] relative to infrared analysis of struvite, dittmarite, and newberite. Vibrations localized at 1030 and 571 cm −1 are characteristic of the mono-phosphate group.…”

Influence of airflow rate and substrate nature on heterogeneous struvite precipitation

“…In the 1700-1500 cm − 1 region a broad, weak band is detected that is ascribed to δ H 2 O vibration suggesting the existence of different environments for water molecules. Nevertheless, these experimental data are in full agreement with the recent publications [24][25][26] regrarding infrared analysis of struvite, dittmarite, and newberite.…”

Evaluation of fluoride removal from water by hydrotalcite-like compounds synthesized from the kaolinic clay

“…The kinetic curves show that the equilibrium time and adsorption capacity of K sd P10-(500) and K liq P10-(500) are similar.We observed that adsorption of fluoride is a fast process on HT-like compounds. This behaviour has already been reported in the adsorption of anionic species on HT-like compounds [34].…”